Pull tab secured to tear strip by concentric rivet formation



Sept. 28, 1965 J. HENCHERT 3,208,628

PULL TAB SECURED TO TEAR STRIP BY CONCENTRIC RIVET FORMATION OriginalFiled Feb. 10, 1961 INVENTOR Jul-m HEucHEzT United States Patent ice3,208,628 PULL TAB SECURED TO TEAR STRIP BY CONCENTRIC RIVET FORMATIONJohn Henchert, Oak Park, Ill., assignor to Continental Can Company,Inc., New York, N.Y., a corporation of New York Original applicationFeb. 10, 1961, Ser. No. 88,473, now Patent No. 3,151,766, dated Oct. 6,1964. Divided and this application June 19, 1963, Ser. No. 289,015 3Claims. (Cl. 22054) This invention relates in general to new and usefulimprovements in means for opening containers, such as cans, and moreparticularly is directed to a novel tear strip arrangement forcontainers including metal can ends wherein a container may be opened bymerely grasping a pull tab attached to a tear strip and removing thetear strip to thereby remove a panel of the container.

This application is a division of my copending application Serial No.88,473, filed February 10, 1961, now Patent No. 3,151,766.

One of the primary objects of this invention is to provide a novel tearstrip and pull tab combination wherein the pull tab is firmly anchoredto one end of the tear strip and is of a greater width than the tearstrip whereby the pull tab rests upon the associated container member onopposite sides of the tear strip to reinforce the tear strip at itsstarting end to eliminate the accidental rupture of the container memberat the starting end of the tear strip.

Another object of the invention is to provide a novel connection betweena tear strip and a pull tab therefor wherein the tear strip is in no waypunctured and a good mechanical connection is obtained between the tearstrip and the pull tab without the utilization of a welding process.

A further object of this invention is to provide a pull tab and tearstrip connection wherein the pull tab is provided with a simple bosswhich is passed through an opening in a tear strip and the boss upset toboth form an interlock between the tear strip and the pull tab and toseal the opening in the tear strip.

Another object of the invention is to provide a novel mechanicalconnection between a metal pull tab and a metal tear strip wherein thepull tab and tear strip are provided with interlocked bosses and withportions of the pull tab extending into the tear strip to thus providethe desired mechanical connection without rupturing or otherwisepuncturing the tear strip.

This invention also proposes to provide means to facilitate the startingof the tearing of a tear strip from the adjacent metal whereby the tearstrip is provided with a generally semi-circular end portion which isscored more deeply than side edge portions of the tear strip, whereby alesser starting force is required to rupture the tear strip along thescore lines.

With the above, and other objects in view that will hereinafter appear,the nature of the invention will be more clearly understood by referenceto the following detailed description, the appended claims and theseveral views illustrated in the accompanying drawings.

In the drawings:

FIGURE 1 is a perspective view of an upper portion of a can having ametal can end which is provided with a tear strip and pull tab inaccordance with this invention.

FIGURE 2 is a perspective view similar to FIGURE 1 and shows the tearstrip partially removed.

FIGURE 3 is an enlarged plan View of the upper end of the can of FIGURE1 and shows further the details of the tear strip and pull tab.

FIGURE 4 is an enlarged fragmentary vertical sec- 3,208,628 PatentedSept. 28, 1965 tional view taken along the line 4--4 of FIGURE 3, andshows the specific details of the connection between the pull tab andthe tear strip.

FIGURE 5 is an enlarged fragmentary transverse vertical sectional viewtaken along the line 5-5 of FIG- URE 3 and shows further the details ofthe connection between the pull tab and tear strip, including the factthat the pull tab overlies the metal can end on opposite sides of thetear strip to prevent the accidental rupturing of the can end along theoutline of the tear strip by a downward pressure.

FIGURE 6 is a fragmentary plan view showing the general outline of thetear strip at the starting end thereof and the formation of the scorelines defining the same.

FIGURE 7 is an enlarged fragmentary vertical sectional view taken alongthe line 77 of FIGURE 6, and shows the specific arrangement of thescores in the various portions of the metal can end along the outline ofthe tear strip.

Reference is first made to FIGURES l, 2 and 3, wherein there isillustrated a conventional type of can which is generally referred to bythe numeral 20, and which includes a can body 21 and a can end 22. Thecan end 22 is preferably formed of a light gauge metal, and it isdesirable that the metal be easily rupturable. As a result, normally thecan end 22 will be formed of aluminum, although the usual metalsemployed in the making of the can ends may be utilized. The can end 22is secured to the can body 21 by a conventional seam 23. The can 20 isillustrated and described only to set forth one environment of theinvention. The present invention is not restricted to cans, but may beused in all types of containers, etc., where it is desired to remove aportion thereof without utilizing any opening equipment, such as a canopener in the case of a can.

Reference is now made to FIGURE 3 in particular, wherein the can end 22is illustrated as having a circumferential tear strip 24 which isdefined by a pair of score lines 25, 26 with the score line 25 beingdisposed outermost and being disposed adjacent the seam 23 so that whenthe tear strip 24 is removed, substantially the entire can end 22 withinthe seam 23 will be removed. The score lines 25, 26 are disposedgenerally in concentric relation for the most part of their lengths andthe score line 26 generally defines an inner panel 27.

In order to facilitate the tearing and removal of the tear strip 24 fromthe can end 22, there is provided a pull tab, generally referred to bythe numeral 28. The pull tab 28 is relatively elongated and is of agreater width than the tear strip 24. The peripheral edges of the pulltab 28 are reinforced by a narrow peripheral flange 29 which is bentover the upper surface of the pull tab 28, as is best shown in FIGURES3, 4 and 5.

It will be seen from FIGURES 4 and 5 that the connection between thetear strip 24 and the pull tab 28 includes an integral boss 30 on thetear strip 24, which boss 30 projects downwardly into the interior ofthe can and leaves a closed opening 31 through the tear strip 24. Thepull tab 28 is provided with a similar boss 32 which is of a size to besnugly received within the boss 30.

After the pull tab 28 has been loosely assembled with the tear strip 24,the bosses 30 and 32 are offset to have the relationship shown inFIGURES 4 and 5. The offset bosses 30 and 32 now include a relativelylarge diameter bead on the boss 30 below the surface of the tear strip24 and have a portion thereof snugly engaging in a manner whereinaccidental rupture of the connection between the pull tab and tear stripis precluded, thus assuring the tearing of the tear strip from the canend 22 when it is desired to open the can 20.

The advantages of the pull tab and tear strip construction discosedherein will be obvious in that not only is the pull tab securelyconnected to the tear strip in a manner to assure the removal of thetear strip when desired, but also the connection has been accomplishedin a simple mechanical metal working operation without forming anyopening in the tear strip which will be susceptible to leakage.

Reference is now made to FIGURES 6 and 7, wherein the details of thescore lines defining the various tear strips at the starting end of eachtear strip, are shown. For identification purposes only, the partial canend illustrated in FIGURE 6 will be considered to be the can end 22, andthe tear strip, the tear strip 24. As was previously described, the tearstrip 24 is defined by a pair of score lines 25, 26. As is bestillustrated in FIGURE 7, these score lines 25, 26 are relativelyshallow. The score lines 25 and 26 will preferably be of a depth so thatthe remaining metal to be torn in the removal of the tear strip 24 willhave a thickness of 0.003 inch. The ends of the score lines 25, 26 areconnected together by a generally semi-circular score line 102 which hasa greater base width and is of a greater depth, as is best illustratedin FIGURES 6 and 7. The depth of the score line 102 will be such that inmost instances, the remaining thickness of metal to be torn will rangebetween 0.001 inch and 0.0015 inch. By making the score line 102 muchdeeper than the score lines 25, 26, it will be readily apparent that asharp upward pull on the starting end of the tear strip 24 by means ofthe pull tab 28 will result in the rupturing of the metal of the can end22 along the score line 102. Once the initial rupturing has beenaccomplished, the tear strip 24 may be removed by continuously exertingan upward pull thereon with the tear strip 24 being torn from the canend 22 along the tear lines 25, 26.

The advantage of the relatively deep score line 102 coupled with thesupporting feature of the individual pull tab is obvious. Applicant hasmade the initially torn portion of the can end of sufiicient weakness tofacilitate the ease of tearing the starting end of the tear striptherefrom. On the other hand, by making each pull tab of a sufiicientwidth to engage the can end outwardly of the tear strip, the tear stripis prevented from deflecting inwardly due to any accidental forceexerted thereon, whereby the can 20 would be opened prematurely.

From the foregoing, it will be seen that novel and advantageousprovision has been made for carrying out the desired end. However,attention is again directed to the fact that variations may be made inthe examples of the invention disclosed herein without departing fromthe spirit and scope of the invention, as defined in the appendedclaims.

I claim:

1. A tear strip assembly comprising a panel, a tear strip defined insaid panel by spaced weakening lines in said panel, said tear striphaving a starting end, and a pull tab overlying and connected to saidtear strip starting end for facilitating the removal of said tear strip,said pull tab being of a greater width than the underlying portion ofsaid tear strip and resting on said panel outwardly of said tear stripto resist accidental rupturing of said panel by inwardly displacement ofsaid tear strip starting end, said weakening lines including a weakeningline extending around a terminal portion of said tear strip startingend, said last mentioned weakening line presenting a line of leastresistance to tearing to facilitate the starting of the removal of saidtear strip, said tear strip having an opening defined by an inwardlydirected first boss with said tear strip being imperforate, said pulltab having a second boss extending into the tear strip opening andtelescoped within said first boss, said weakening lines being in theform of score lines and said lastmentioned weakening line being of agreater depth than others of said weakening lines.

2. A tear strip assembly comprising a metal tear strip having a startingend, said starting end having an opening therein, a pull tab having anintermediate plug portion extending into said opening and engaged behindsaid tear strip to secure said pull tab to said tear strip, said tearstrip opening being defined by a boss on said tear strip whereby saidtear strip is imperforate, and said pull tab being formed of sheet metalwith said plug portion also being in the form of a boss, said bossesbeing internested and interlocked by means of internested beads.

3. A tear strip assembly comprising a metal tear strip having a startingend, said starting end having an opening therein, a pull tab having anintermediate plug portion extending into said opening and engaged behindsaid tear strip to secure said pull tab to said tear strip, said tearstrip opening being defined by a boss on said tear strip whereby saidtear strip is imperforate, and said pull tab being formed of sheet metalwith said plug portion also being in the form of a boss, said bossesbeing internested and interlocked by means of internested beads, saidsecond boss having a flattened bead and said first boss having an openbead snugly receiving said flattened bead.

References Cited by the Examiner UNITED STATES PATENTS 1,792,897 2/31 DeLacy 220-24 2,029,329 2/ 36 Ljungstrom et al 220-52 2,557,830 6/51Lazarevich 215-46 2,963,197 12/60 Lyon 220-74 2,978,140 4/61 Walsh.

THERON E. CONDON, Primary Examiner.

1. A TEAR STRIP ASSEMBLY COMPRISING A PANEL, A TEAR STRIP DEFINED INSAID PANEL BY SPACED WEAKENING LINES IN SAID PANEL, SAID TEAR STRIPHAVING A STARTING END, AND A PULL TAB OVERLYING AND CONNECTED TO SAIDTEAR STRIP STARTING END FOR FACILITATING THE REMOVAL OF SAID TEAR STRIPSAID PULL TAB BEING OF A GREATER WIDTH THAN THE UNDERLYING PORTION OFSAID TEAR STRIP AND RESTING ON SAID PANEL OUTWARDLY OF SAID TEAR STRIPTO RESIST ACCIDENTAL RUPTURING OF SAID PANEL BY INWARDLY DISPLACEMENT OFSAID TEAR STRIP STARTING END, SAID WEAKENING LINES INCLUDING A WEAKENINGLINE EXTENDING AROUND A TERMINAL PORTION OF SAID TEAR